Control of mating-type-related functions in the yeast Saccharomyces cerevisiae involves the action of regulatory genes acting on functions that are also modulated by cell-cell interactions mediated by peptide mating pheromones. The aim of this project is to understand the mechanisms of these control processes in physiological and molecular terms. Our approach combines the use of rapid and sensitive tests for several regulated functions, with temperature-sensitive mutants and gene-cloning methodology, to analyze the molecular and related physiological events. Mutants are used to associate genes with their physiological functions. The cloned genes will be used as probes and for DNA sequencing, to permit identification of the structural genes, and to characterize their regulation at transcription. Genetic and physiological methods will be used to identify the gene products and ascertain their biological functions. The project makes use of conventional genetic, molecular and physiological methods and insights. Our long-term goal is to develop an understanding of the processes involved in this regulation in terms than can be related to regulation in development in higher organisms. The similarity between the peptide pheromones and peptides hormones in mammals makes this goal attractive. The similarity at this time is a formal one. We hope to learn whether it has a more fundamental basis, as well. It is in this possibility that the health-relatedness of the work is to be found.